Bag comprising slide-actuated closing profiles

ABSTRACT

A bag which includes additional closing profiles which are respectively actuated by a slide during opening and closing. The bag includes a wall portion which forms a veil which can be broken and which is designed in such a way that it covers the slide before the bag is used.

FIELD OF THE INVENTION

The present invention relates to the field of bags having complementaryclosure strips actuated both in opening and in closing by a slide.

BACKGROUND OF THE INVENTION

Such bags are described, for example, in documents EP-A-0 051 010,EP-A-0 102 301, and EP-A-0 479 661.

Such bags that are opened and closed by a slide have already given goodservice.

The slides make it easier to open and close the bags. The presence of aslide is particularly appreciated by the elderly or the visuallyhandicapped.

Nevertheless, in spite of their advantages, bags with slides are not atpresent as widespread as expected.

The object of the present invention is to improve this field.

SUMMARY OF THE INVENTION

This object is achieved in the context of the present invention by a bagincluding complementary closure strips actuated both for opening and forclosing by a slide, the bag being characterized by the fact that itincludes a portion of the bag wall that forms a web that is suitable forbeing broken and that is designed to cover the slide before the bag isused.

As will be understood on reading the description below, the presentinvention thus uses simple means to prevent access to the slide so longas the covering web is in place.

This avoids any manipulation, whether accidental, innocent, or withcriminal intent, particularly on the shelves of large stores.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics, objects, and advantages of the present inventionwill appear on reading the following detailed description with referenceto the accompanying drawing, given by way of non-limiting example and inwhich:

FIG. 1 is a section view through a bag of the invention, during a stepof fixing part of the closure strips to the walls of the bag;

FIG. 2 is a section view through the same bag, after it has been opened;and

FIG. 3 is a view similar to FIG. 1 showing a bag constituting a variantembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a bag 10 made up of two parallel walls 12, 14 defining abag mouth 16.

The general structure of such a bag can be made by numerous dispositionsknown to the person skilled in the art.

Thus, for example, the two walls 12, 14 of the bag can be made from acommon sheet which is folded in half so as to form two generallyparallel flaps corresponding to said walls 12, 14 which are fixedtogether around three sides of their periphery, e.g. by adhesive or byheat-sealing.

Under such circumstances, the mouth 16, which preferably corresponds toa zone in which the two walls 12, 14 are joined by adhesive orheat-sealing, can be parallel to and opposite from the fold line in thesheet, or it can be perpendicular to said fold line (in which case thebottom 19 of the bag is likewise formed by sticking or heat-sealingtogether the two flaps 12, 14, as shown in non-limiting manner in FIG.1).

In a variant, the two walls 12, 14 can be made from two initiallyseparate sheets that are generally parallel to each other and fixedtogether around their periphery over four sides, e.g. by adhesive or byheat-sealing, as mentioned above.

Bags of the present invention are fixed with complementary closurestrips 20, 30 that are actuated by a slide 40.

These means can be embodied in numerous ways that are known inthemselves.

Thus, for example, the complementary closure strips 20, 30 can be maderespectively of complementary male/female type structures or they can bemade of structures comprising complementary hooks.

The person skilled in the art knows numerous shapes for complementaryclosure strips as described in the literature and/or as on sale atpresent. That is why the shapes of the closure strips 20, 30 are notdescribed in greater detail below.

The same applies to the slide 40.

It too can be embodied in numerous different ways.

In particular, the slide 40 can comply with the dispositions describedin document EP-A-0 479 661.

That is why the slide 40 is not described in detail below.

Nevertheless, it should be observed that the slide 40 is preferably madeof plastics material and comprises two side flanges interconnected via abase and co-operating with an elongate central tongue to define twoconverging passages for the mutually-engageable complementary closurestrips 20, 30. Thus, when the travel direction of the slide 40 relativeto the closure strip 20, 30 tends to move the slide 40 so as to forcethe closure strips 20, 30 into engagement, the bag is closed. When theslide 40 is moved in the opposite direction, the bag is opened.

The film(s) constituting the walls 12, 14 of the bag can be embodied innumerous ways; The film is preferably made of a plastics material, verypreferably of poly-olefin, most advantageously of low or high densitypoly-ethylene or indeed polypropylene. Nevertheless, the invention isnot limited to these particular materials.

The invention also applies to bags made of composite material, forexample a sheet based on plastic- or metal-coated paper, etc. . . .

The complementary strips 20, 30 are carried by respective support webs22, 32 fixed to the walls of the bag as described below.

In the embodiment shown in accompanying FIG. 1, a first one of thesupport webs 22 is fixed to the inside surface 13 of a wall 12 at adistance from the line of heat-sealing 17 defining the mouth 16. In FIG.1, the connection zone between the support web 22 and the wall 12 isgiven overall reference 24. This connection zone can be defined byadhesive or heat-sealing between the inside surface 13 of the wall 12and the support web 22. Where appropriate, and as is known to the personskilled in the art, this connection zone 24 can be defined, for example,by heat-sealing ribs that are integrally extruded on the support web 22and/or the wall 12.

The second support web 32 in the embodiment shown in FIG. 1 issandwiched between the two walls 12, 14 at the mouth 16, and it is fixedto them at the connection 17.

More precisely, a connection 17 a is defined between a first face of thesupport web 32 and the wall 12, and a second connection 17 b is definedbetween the second face of the support web 32 and the second wall 14.

It will be observed, and this constitutes an important advantage of theinvention, that the connection defined in this way between the supportweb 32 and the walls 12, 14 can be implemented using conventionalheat-sealing jaws of the kind commonly used for closing a bag at itsmouth by connecting together the walls 12 and 14 of the bag directly inthe conventional manner. Such heat-sealing jaws are referenced 100 and110 in FIG. 1.

The person skilled in the art will readily understand that the wallportion 12 situated between the connections 24 and 17 a thus originallycovers the slide 40 so as to prevent direct access thereto.

However, once this portion of the wall 12 has been broken, the user hasfree access in conventional manner to the slide 40 both for opening andfor closing the bag by separating or interfitting the strips 20, 30.

For this purpose, the above-specified portion of the wall 12 can beprovided with a line of weakness 11 which extends parallel to theconnections 24, 17 a so as to make this portion of the wall easier toopen.

Furthermore, as shown diagrammatically in FIG. 1, it is preferable forthe length L1 of the above-specified portion of the wall 12 situatedbetween the connection zones 24 and 17 a, i.e. the distance L1 betweenthe connection zones 24 and 17 a when the portion of the wall 12 betweenthem is under tension, to be less than the sum of the correspondinglengths L2 and L3 of the support webs 22 and 32 situated between theconnection zones 24 and 17 a. The person skilled in the art willunderstand that complying with this geometrical condition facilitatesaccess to the slide 40 and to the strips 20, 30 through the opening 11formed in the portion of the wall 12 situated between the connectionzones 24 and 17 a after said wall portion has been broken.

This access is shown diagrammatically in FIG. 2.

The bags shown in FIG. 1 are preferably made on a form, fill, and seal(FFS) type machine, i.e. a machine for performing automatically theoperations of forming bags, filling them, and closing them. The generalstructure of such conventional machines is not described in detailbelow.

Nevertheless, it is recalled that FFS machines generally comprise aforming throat which receives as input the film in the flat state comingfrom a reel, and which outputs the film shaped into a tube, a fillingchute which opens out into the forming neck and consequently into saidtube, means for feeding closure strips and for fixing them to the film,longitudinal heat-sealing means for closing the tubes longitudinally,and means suitable for operating sequentially to generate a firsttransverse line of heat-sealing before content is inserted into the tubevia the filling chute, and then a second transverse line of heat-sealingonce the content has been inserted into the tube, so as to close apackage around the content.

In this context of an FFS machine, in the present invention, the supportwebs 22, 32 carrying the closure strips 20, 30 and the slide 40 arepreferably brought to the film transversely to its travel direction andupstream from the forming neck. More precisely, in this embodiment, thesupport web 22 is fixed to the film 12 in the connection zone 24 usingappropriate means, and in particular heat-sealing jaws, upstream fromthe forming neck, while the second support web 32 is fixed to the walls12 and 14 in the connection zone 17 by means of the heat-sealing jaws100, 110 when the above-mentioned “second” line of transverseheat-sealing is made.

Nevertheless, the invention is not limited to having the support webs22, 32 disposed transversely to the direction in which the filmadvances. The invention can equally be applied to feeding the supportwebs 22, 32 together with the closure strips 20, 30 and the associatedslide 40 longitudinally, i.e. parallel to the direction in which theabove-mentioned film advances. Under such circumstances, the supportwebs 22, 32 are fixed on the walls 12, 14 not by means of transverseheat-sealing jaws, but by means of longitudinal jaws, i.e. jaws situatedparallel to the direction of the forming neck, e.g. the conventionaljaws used for longitudinally closing the tube that is obtained at theoutlet from the forming neck.

It will be observed that in the event of the support webs 22, 32 beingplaced longitudinally, the two connection zones 17, 24 can be madesimultaneously and not successively as described above when they wereput into place transversely respectively upstream and downstream fromthe forming neck.

FIG. 3 shows a variant embodiment in which one of the support webs (inthis case referenced 32 and situated adjacent to the mouth 16) is itselfmade up of two segments 32 a, 32 b, with one of the segments 32 asituated adjacent to the mouth 16 and fixed to the walls 12, 14 in zones17 a, 17 b as described above, while the other segment 32 b is situatedadjacent to the strip 30, and with the two segments 32 a, 32 b forming adihedral whose concave side is directed towards the outside, i.e.towards the wall 12. Under such circumstances, the two segments 32 a, 32b can be constituted by elements that are initially separate and thatare connected together by adhesive or by heat-sealing at the ridge 33 ofthe above-specified dihedral or can indeed be constituted by a singleelement that is folded onto itself via a sharp angle at said ridge 33.

The person skilled in the art will also understand that by using aportion of wall so that it initially covers the slide it is possible tosolve in simple manner problems associated with sealing that aregenerally encountered in bags fitted with slide-actuated closure strips.Naturally, to ensure that bags are sealed sufficiently after the wall 12has been broken, and after the slide 40 has been manipulated, i.e. afterthe bag has been opened, the support webs 22, 32 and/or the closurestrips 20, 30 and/or the slide can be provided with numerousdispositions for providing sealing, and in particular those defined bythe Applicant in French patent applications FR 98/16236, FR 98/13732, FR98/13734, and FR 98/05681.

Naturally, to ensure that the bag is sealed, it is necessary for the endzones of the support webs 22, 32 extending transversely to theconnection zones 24, 17 also to be sandwiched between the side edges ofthe walls 12, 14 and fixed thereto.

Naturally, the present invention is not restricted to the particularembodiments described above, but extends to any variants within thespirit of the invention.

What is claimed is:
 1. A bag comprising complementary closing stripsactuated both for opening and for closing by a slide, the bag includinga portion of the bag wall that forms a web that is suitable for beingbroken and that is designed to cover the slide before the bag is used,the closure strips being carried by respective support webs, one ofwhich is fixed to the inside surface of a wall of the bag at a distancefrom a mouth thereof, and the other of which is fixed to at least onewall of the bag at the mouth, said other support web being made up oftwo segments, one segment adjacent to the mouth and the other adjacentto the strip, the segments constituting a dihedral whose concave side isdirected towards the outside of the bag, and towards the web that can bebroken and that initially covers the slide.
 2. The bag according toclaim 1, wherein the other support web is sandwiched at the mouthbetween two walls of the bag and is fixed to each of them at the mouth.3. The bag according to claim 1, wherein the length of said portion thatcan be broken and that covers the slide, as measured between twoconnection zones for the webs carrying the closure strip, is less thanthe sum of the lengths of said support webs situated between saidconnection zones.
 4. The bag according to claim 1, wherein the breakableweb covering the slide is provided with a line of weakness.
 5. The bagaccording to claim 1, wherein the web that initially covers the slide isconstituted by a portion of one of the walls of the bag, while theclosure strips are placed on support webs that are fitted to the wallsof the bag.